Transfer data from application page to a form.

I have created a business object named InventoryItem. I am able to create an InventoryItem page that can create a new item and place it in a table the same way that the Getting Started tutorial did with Travel Request. (this includes the pool and diagram)

Now, from this application page, I want to be able to open another form so that I can modify the selected row in the table. How do I pass the data from the selected row into the new form?